A joint China-U.S. declaration on climate change is a political reset to a time when the world¡¯s two biggest carbon emitters reached the brief meeting of minds that helped forge the 2015 Paris Agreement.

But that still won¡¯t be enough to avert a deepening climate crisis, unless Washington and Beijing can match words with more action to curb fossil fuels and prod others at the COP26 talks in Glasgow to do the same.

¡°It prevents the worst from happening,¡± said Li Shuo, senior climate analyst with Greenpeace in Beijing, hinting at a scenario under which the United States and China might refuse to cooperate in the fight against climate change. ¡°But does it give us the best? The answer is clearly no.¡±